According to a known technique, an annular combustion chamber comprises two coaxial internal and external walls of revolution connected together upstream by a so-called chamber bottom annular wall which comprises openings for the passage of fuel injector heads between the internal and external walls of revolution. Each injector is engaged in centring means which can move in the radial direction in support means integral with support means.
In the current technique, the centring means of each fuel injector is formed in a centring ring, wherein an injector is engaged, and comprising a radial annular collar which radially extends outwards and is mounted to slide in an annular groove of the support means.
The groove of the support means enables a radial displacement of the centring ring accommodating the injector so as to compensate for the manufacturing tolerances as well as the differential expansions in operation.
The annular groove for the radial displacement of the ring is defined by means of axial retention in the upstream direction and in the downstream direction of the radial annular collar of the centring means. In practice, the means of axial retention in the downstream direction consist of a downstream radial wall of an annular sheath fixed on the bottom of the annular chamber, with the radial wall being connected to a cylindrical rim which extends in the upstream direction and whereon a washer inserted on the cylindrical rim is welded or brazed.
Such washer is thus permanently fixed on the support means. When all or a part of the centring means of an injector must be replaced during a maintenance operation, this washer has to be broken, which is a delicate operation since the sheath which is fixed on the annular wall of the bottom of the chamber must not be damaged. Besides, weld beads breaking have been noted, which is not admissible, and does not ensure a perfect mechanical integrity of the fuel injection systems.